The fast dynamics observed in the dication track the electron-correlation driven population of the highly excited states of the naphthalene cation [1]}, [2]}. These states are located just below the double ionization threshold and only one or two IR photons are sufficient to further ionize the molecule. The decay time of \(\tau _1=30\pm 1\)  fs extracted from the fit is in the good agreement with the timescale that was reported previously [1]}. The rise time \(\tau _2=7\pm 1\)  fs has not been reported previously. We note that this timescale represents delayed rise of the dication signal. A similar delay has previously been observed in benzene [4]} and phenylalanine [5]}. Galbraith and co-authors elaborated that this timescale may correspond either to ultrafast electronic relaxation of the initially excited state or to dynamics in the Frank-Condon region.
